well in bulk move in admin it moves all images from one category to another.
Code:
Content visible to verified customers only.
It is quite simple we use move_image_cat function which calls move_image
So if it stops it is stopping because permissions on some file is strange and it cant do it. We only move an image if one exists as noted here
Code:
Content visible to verified customers only.
I would need alot more info and hands on look to see what might be your issue honestly
The only way you can get the error your noting is if the filename is not valid in the database that I see where we are trying to copy nothing to nothing. Note there is no image in your error.